You have downloaded a rogue Anti-Spyware App that forces the user to download their software and then wants you to pay for resolving the threats. Uninstall if you can and then follow these steps below:
If you can't access anything on the Internet, then bootup your computer in safe mode. You can do this, when you see black screen press F8.
Then Scan with an anti-virus and anti-spyware app.
The best security apps are free. Yes, free.
I recommend Avast Anti-Virus which you can download from here:
The all time best anti-spyware app is Ad-Aware, and you can download this from here:
Ad-aware has been in the top 5 most downloaded items for more than a year now on download.com.
Scan your computer and remove any threats.
After you have done this, if you have Windows XP, I strongly recommend you install Windows SP2 or even SP3 which is now currently out. Just start Windows Update and it should come up with a list of updates for your computer. If you hardly run computer updates then you could have to wait for a long time.
If you still keep getting the popup box after you scanned, I recommend downloading a very small tool called "Hi-Jack this" scan your computer with this tool, and then copy and paste the code onto their forums. People will analysis it and see if anything needs to be removed.
You can download Hi-Jack this from this URL:
Now, after all the threats have been removed, delete cookies, history, and Cache by right clicking on Internet Explorer and click properties. Then delete all cookies, Internet Files, and history their.
After this run disk defragmenter and disk cleanup for Optimum Performance. If you never run disk defragmenter then this can take up to several hours before completion. If you can't wait that long download free this disk defrag which is much better and is much faster too:
If you still have problems then try Windows Restore. If this still fails, the only thing I can think of is installing Windows again.
To prevent this from happening in the future, use Avast RealTime protection AND use this free effective firewall too:
Hope I have been help!!!